Recently, Japan's population has been aging with a declining birth rate at an unprecedented rate compared to that worldwide, and Kumamoto Prefecture is no exception. In this chapter, we examine whether the recent changes in vital statistics have affected the incidence of glioma based on data from the latest Kumamoto Prefecture Brain Tumor Data Bank. We compare the age-adjusted incidence of glioma extracted from the Brain Tumor Registry of Japan and Central Brain Tumor Registry of the United States(CBTRUS)for the period from 1990 to 2017 when data on the annual transition of the population composition in Kumamoto Prefecture were obtained. This chapter also outlines whether there are differences in survival rates between Japan and the United States. We hope that this chapter will help you determine the future direction of glioma treatment in Japan.